Whether or not they arrive en-mass in the home, 3D printers have many promising areas of potential future application. They may, for example, be used to output spare parts for all manner of products, and which could not possibly be stocked as part of the inventory of even the best physical or even online store. Hence, rather than throwing away a broken item (something unlikely to be justified a decade or two hence due to resource depletion and enforced recycling), faulty goods will be able to be taken to a local facility that will call up the appropriate spare parts and simply print them out. 3D printers may also be used to make future buildings. Demonstrating the potential, over in China an amazing company called WinSun Decoration Design Engineering has already 3D printed a number of houses. Produced using a vast material extrusion 3D printer, these include a 1,100 square meter mansion and a five storey apartment block. Another future application is the use of 3D printers to creat…

According to the American Society of Manufacturing Engineers, direct digital manufacturing (DDM) refers to the 'the process of going directly from an electronic digital representation of a part to the final product via additive manufacturing'. On occasion, some such final products may be molds or other items of tooling as mentioned above. However, in industrial sectors including space, aerospace, automotive manufacture, healthcare, toy making, art-and-crafts, designer goods and fashion, we are starting to witness the application of 3D printing to directly fabricate final products or parts thereof. The drivers of the DDM Revolution are multitudinous, and include the ability to use 3D printing to optimize the geometry of final parts (often saving raw materials in the process); to make parts with geometries that could not be created via traditional means; and to make low-run, highly customized products that would be not cost effective to manufacture without 3D printing. 3D print…

Since the late 1980s, 3D printing has been used to create prototypes and concept models. These can significantly speed and otherwise assist design and pre-production processes, and as a result can save companies a great deal of money as well as improving the function of final products. Material extrusion 3D printers costing a few thousand and even sometimes a few hundred dollars can now make decent prototypes in many situations. More expensive 3D printers based on material jetting or powder bed fusion can now also produce highly detailed, functional prototypes out of a wide range of materials, and increasingly in full colour. There is even already a 3D printer -- the DragonFly 2020 -- that can 3D print prototype circuit boards. Prototypes 3D printing molds and other tooling The fastest growing area of 3D printing application is the additive manufacture of production tools. Traditionally, the molds, patterns, jigs, fixtures and other tooling used to make final products has been hand …

Powder bed fusion uses a laser, electron beam or other heat source to selectively fuse successive powder layers. The technology goes by a great many proprietary names, including 'laser sintering' (LS), 'selective laser sintering' (SLS) 'direct metal laser sintering (DMLS), 'selective heat sintering' (SHS), laserCUSING and 'electron beam melting' (EBM). Build materials range from plastics -- such as nylon -- to metals that include aluminium, copper, steel, nickel alloys, cobalt chrome, iron, titanium and high performance Inconel alloys. It is also possible to create objects using new composite materials such as 'alumide', which is a powdered mix of nylon and aluminium. Powder bed fusion Powder bed fusion is currently both expensive and complex to master. Even so, the technology is starting to be used to produce very high quality industrial parts, including fuel injectors and other aerospace and rocket components. It is also already possible…

Material jetting uses a print head to spray liquid layers that are usually then solidified by exposure to UV light. This again offers very high resolution 3D printing, and is even capable of producing multi-colour and multi-material output by spraying several different materials from a multi-nozzle print head in varying combinations. The latest material jetting 3D printer from Stratasys -- the J750 -- can fabricate objects out of six different materials (both rigid and flexible) in up to 360,000 colours, and with a 0.014 mm (14 micron) layer resolution. Material jetting remains an expensive 3D printing technology, but as the images below demonstrate, the results can be spectacular. Material Jetting In the near future, a new material jetting technology called 'NanoParticle Jetting' (NPJ) is due on the market. Developed by Xjet (who also developed the above material jetting technology now owned by Stratasys), this jets solid metal nanoparticles within a liquid suspension, so …

Vat photopolymerization uses a laser or other light source to solidify successive object layers on the surface or base of a vat of liquid photopolymer. The very first commercial 3D printer was based on a vat photopolymerization technique called 'stereolithography'. This was invented by Charles Hull in 1984, who subsequently founded 3D Systems. Stereolithographic 3D printers (known as SLAs) position a perforated platform just below the surface of a vat of liquid photopolymer. A UV laser beam then traces the first slice of an object on the surface of this liquid, causing a very thin layer of photopolymer to harden. The perforated platform is then lowered very slightly and the process repeats until a complete object has been printed out. Another vat photopolymerization technology is 'DLP projection'. This uses a projector to solidify object layers one complete cross-section at a time. One of the leading manufacturers of this kind of 3D printer is EnvisionTEC. Vat photo…

Material extrusion uses a nozzle to extrude a semi-liquid material to create successive object layers. Most usually the 'build material' is a thermoplastic such as acrylonitrile butadiene styrene (ABS), polycarbonate (PC), nylon, or the bioplastic polylactic acid (PLA). Whatever material is used, it is usually delivered to a print head as a solid, thin strand or 'filament' that is then heated into a molten state. Today, material extrusion is the most common 3D printing process. The technology was invented by Scott Crump in 1988, who set up a company called Stratasys to commercialize his invention. Crump chose to name the technology 'fused deposition modelling' or 'FDM', and patented and trademarked these terms. Hence, while many people use the phrase 'FDM' to refer to this kind of 3D printing, only Stratasys actually makes FDM 3D printers. Other manufacturers refer to the same process as 'thermoplastic extrusion', 'plastic jet print…